Many magnetic, and some optical, data storage systems of the disc type include read/write transducer systems with flying head/gimbal assemblies (HGA's) to provide a constant air gap between the transducer and the disc during read/write operations. This air gap is on the order of a few microinches to tens of microinches so that it is wide enough to prevent the transducer from crashing against the disc surface, and still narrow enough to prevent data error due to dropout.
The read/write transducer system for a magnetic disc system comprises a read/write head arranged along one edge of a "slider" that has an aerodynamic planar surface designed to lift it away from the surface of the disc when the disc is spinning. The read/write transducer system for an optical disc system has a lens system that is attached to or passes through the body of the slider. The slider is attached to a flexible gimbal, or "flexure," and the flexure is in turn mounted to a "load beam," generally comprising a cantilever spring member to provide a bias force opposed to the force of the air cushion lifting the slider away from the disc surface. The HGA generally comprises the combination of the slider and the flexure. The HGA is attached to the disc drive actuator arm with the load beam. The actuator arm is rotated by the disc drive transducer servo system to provide tracking for the read/write head in the HGA. The height of the actuator arm relative to the disc surface is adjusted so that the HGA flies above the surface of the disc with the required air gap as the disc rotates.
It is essential that the flexure have sufficient compliance to allow the slider sufficient freedom of pitch and roll to maintain the desired constant air gap as the slider glides on the air cushion above the disc surface. Failure to maintain an adequate air gap can cause the transducer to "crash" against the disc surface. Allowing an air gap that is too far or close can cause data storage and retrieval error.
In an effort to reduce the weight of the HGA and improve performance, among other things, the slider has been reduced in both size and weight. The presently used flexure designs do not have adequate compliance to allow sufficient degrees of pitch and roll with the smaller lift forces developed by the smaller sliders. Although the compliance of the existing flexure designs can be increased, existing flexure designs with increased compliance permit inertial moments to be generated by the mounting of the slider on the flexure, and those inertial moments cause undesirable in-plane motion while track seeking. Some optical disc systems require that a lens system be mounted through the top of the slider. In addition, it has become desirable to mount electrical connections pads for magnetic disc systems on the top of the slider. The presently used in-line flexures physically interfere with these lens systems and electrical connections along the top of the slider.